Finally after 3 years of use, my son stripped the nylon gears
in his rear drive Bafang SWXH 26
Inch wheel model being run by Ecrazyman/keywin 350w/20a Infineon controller and 60V to it.
I had already ordered some metal gears
from keywin a couple of years ago (I don't know if keywin
is around anymore), so I just had to install them. One of the nylon gears
had actually cracked and
jammed the motor. Not wanting to take anymore chances, I used 3 metal gears
Its not too loud when the motor has been treated with ACF 50 or fluid film inside to protect it.
Also a note. The insides of the motor are in good shape, so the above treatment worked and
did its job of protecting the motor though a couple of winters.